A near-to-eye (or near-eye) display is a wearable device that creates a display in front of the user's field of vision. The display may be transparent or opaque, depending on the application. For example, a transparent display can overlay information and graphics on top on the real world, while an opaque display can provide an immersive theater-like experience.
Near-to-eye Displays can be broadly placed in two categories, immersive and see-through. Immersive near-to-eye displays block a user's view of the real world and create a large field of view image, typically 30°-60° degrees for cinema glasses and 90°+ degrees for virtual reality displays. See-through near-to-eye displays leave the user's view of the real world open and create either a transparent image or a very small opaque image that blocks only a small portion of the user's peripheral vision. The see-through category can be broken down into two applications, augmented reality and smart glasses. Augmented reality headsets typically offer 20°-60° degree fields of view and overlay information and graphics on top of the user's view of the real world. Smart glasses, which are really a misnomer, in contrast typically have a smaller field of view and a display at which the user glances periodically rather than looking through the display continuously.
However, such near-to-eye displays employ a number of optical elements including the displays, intermediate lens and prisms, and the user's pupils even without consideration of whether they use prescription refractive correction lenses. As such the optical train from display to pupil within near-to-eye displays introduces distortions and chromatic aberrations into the projected image. Where these near-to-eye displays are projecting real time video data captured by a camera then the distortions and chromatic aberrations of these must be considered as well. In many instances the correction of these distortions and chromatic aberrations requires either the design of the optical train to become significantly more complex through additional corrective elements adding to weight, cost, and size; require complex image processing thereby adding to latency from image acquisition to presentation which has severe impacts after a relatively low latency threshold is exceeded thereby requiring faster electronics with increased cost and power consumption; or a tradeoff in the performance of the near-to-eye display must be made.
Accordingly, it would be beneficial therefore to provide designs of such near-to-eye displays with methods of mitigating these distortions and chromatic aberrations through electronic processing techniques in addition to potential modifications to some optical elements such that low weight, low volume, low complexity, and low cost near-to-eye display systems can be provided to users, both with normal vision or with low-vision. It would be further beneficial to also provide for chromatic distortion correction within the context of exploiting consumer grade higher performance, low cost graphics processing units.
Other aspects and features of the present invention will become apparent to those ordinarily skilled in the art upon review of the following description of specific embodiments of the invention in conjunction with the accompanying figures.